First Alert Hardwire Ion Sensor Carbon Monoxide/Smoke Alarm Smoke and carbon monoxide alarm. Features a carbon monoxide sensor, dual ionization smoke sensor, and separate visual and audible smoke and carbon monoxide indication to eliminate confusion. Intelligent Sensing Technology for fewer nuisance alarms, smart 3-wire interconnect, and Quick-Connect wiring harness for connection to AC alternating current power. Also includes an 85dB horn and 9-volt battery backup. Battery life varies according to use and application. 2 silence features Can silence the low battery chirp for up to 8 hours or temporarily silence an unwanted alarm. Interconnectable with up to 18 devices. 120V AC/DC. 10-year limited warranty. UL Underwriter's Laboratories listed. Type Hardwired, Voltage 120V, Battery Life Varies According To Application, Sensor Type Ionization, Dimensions 5.6 In. W. x 2 In. H. x 5.6 In. L., Battery Back-Up Yes, Alarm Type Smoke Carbon Monoxide, Decibel Level 85dB, Battery Type 9V Battery, Batteries Included Yes, Color White, UL Listed Yes, Warranty 10-Year Limited, Pkg Qty 1, Package Type Box